**2. Materials and Methods**

The filtered cathodic vacuum arc deposition (FCVAD) [27–36] technology was applied to deposit the Ti–TiN–(Ti,Cr,Al)N coatings. A VIT-2 unit, (IDTI RAS—MSTU STANKIN, Moscow, Russia), equipped with two arc evaporators with a pulsed magnetic field and one arc evaporator with filtering of the vapor-ion flow, was used to deposit the coatings. In addition, the system was equipped with a source of pulsed bias voltage supply to a substrate, a dynamic gas mixing system for reaction gases, a system for automatic control of pressure in the chamber and a process temperature control system, and a system for stepless adjustment of planetary gear rotation [27–30,35–42]. The nanolayer structure of the coating provides high hardness at elevated temperatures and high oxidation resistance [27–31,37,38]. A three-layer structure of the coating was assumed [27–31].

The parameters for the process of coating deposition are presented in Table 1.



Note: *I*Ti = current of titanium cathode, *I*Cr = current of Cr cathode, *I*Al = current of aluminum cathode, *p*<sup>N</sup> = gas pressure in chamber, *U* = voltage on substrate.

An analysis of the microstructure and nanostructure of the samples was studied using JEM 2100 (JEOL, Tokyo, Japan) high-resolution transmission electron microscope (TEM) with an accelerating voltage of 200 kV.
